6,367 research outputs found

    Hybrid energy sources for electric and fuel cell vehicle propulsion

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    Given the energy (and hence range) and performance limitations of electro-chemical batteries, hybrid systems combining energy and power dense storage technologies have been proposed for electric vehicle propulsion. The paper will discuss the application of electro-chemical batteries, supercapacitors and fuel cells in single and hybrid source configurations for electric vehicle drive-train applications. Simulation models of energy sources are presented and used to investigate the design optimisation of electric vehicle on-board energy source in terms of energy efficiency and storage mass/volume. Results from a case study considering a typical small urban electric vehicle are presented, illustrating the benefits of hybrid energy sources in terms of system mass and vehicle range. The models and approach can be applied to other vehicles and driving regimes

    A H2 PEM fuel cell and high energy dense battery hybrid energy source for an urban electric vehicle

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    Electric vehicles are set to play a prominent role in addressing the energy and environmental impact of an increasing road transport population by offering a more energy efficient and less polluting drive-train alternative to conventional internal combustion engine (ICE) vehicles. Given the energy (and hence range) and performance limitations of electro-chemical battery storage systems, hybrid systems combining energy and power dense storage technologies have been proposed for vehicle applications. The paper discusses the application of a hydrogen fuel cell as a range extender for an urban electric vehicle for which the primary energy source is provided by a high energy dense battery. A review of fuel cell systems and automotive drive-train application issues are discussed, together with an overview of the battery technology. The prototype fuel cell and battery component simulation models are presented and their performance as a combined energy/power source assessed for typical urban and sub-urban driving scenario

    Hotel housekeeping occupational stressors in Norway

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    Stress is evident in the Norwegian hotel industry and requires urgent attention as portrayed in Annbjørg’s housekeeping managerial occupation. Annbjørg’s occupational stressors derived from weak control of and support for demanding jobs in the housekeeping department and possibly under-reward in comparison to her tireless efforts. Hence, this case study provides a platform for educators, trainers, managers, students and learners to critically examine, discuss and argue managerial occupational stress and interventions set within the Norwegian hotel housekeeping context

    Organic food consumers in Hong Kong

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    Asian organic foods consumers’ behaviour is worth investigating to sustain the continuous growth of organic foods consumption. Hence, Fiona has the ambition to employ the innovation diffusion theory to profile and understand organic foods consumers in Hong Kong in her research proposal. The process of writing an acceptable research proposal is challenging, tedious and time consuming as depicted in Fiona’s experience. Hence, this case study provides the opportunity for educators, students, and organic foods sellers and retailers to discuss and address Fiona’s challenges

    A Cross-Country Comparison of the Relationships Between Strategy, Environment and Control System Attributes: Singapore and Australia.

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    Following the trend towards increased cross-cultural research, this paper reports the results of a study that examines the relationships of strategy, environment, controls and performance in different national contexts viz., Singapore and Australia. A multiple discriminant model was constructed for each country to determine whether the same combination of environmental and control system variables best discriminated between the strategic types in both countries. The results yielded highly significant discriminant functions, indicating that empirical relationships among these variable exits. However, there were differences in the types of discriminating variables between the two countries. In the Singaporean model the control changeability factor loads most heavily in the discriminant function. For the Australian model, dynamism is the most significant discriminator. In terms of environment variables, all three environmental variables (dynamism, hostility and heterogeneity) are significant discriminators for Australia, while only dynamism emerges as significant in the Singapore model. These results suggest that national contexts have an influence on the discriminant functions. Areas for further research are also suggested

    Hotel housekeeping occupational stressors in Norway

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    Stress is evident in the Norwegian hotel industry and requires urgent attention as portrayed in Annbjørg’s housekeeping managerial occupation. Annbjørg’s occupational stressors derived from weak control of and support for demanding jobs in the housekeeping department and possibly under-reward in comparison to her tireless efforts. Hence, this case study provides a platform for educators, trainers, managers, students and learners to critically examine, discuss and argue managerial occupational stress and interventions set within the Norwegian hotel housekeeping context

    Effect of Inflow and Infiltration in Sewerage System of Residential Area, Kuantan, Pahang

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    Inflow and infiltration is a phenomenon in sewerage systems that can have negative effects on the environment and human health if not treated properly. Collaboration has been made between Universiti Malaysia Pahang (UMP) and Indah Water Konsortium Sdn. Bhd. (IWK) where the purpose is to evaluate the amount of inflow and infiltration happening in sewerage systems of residential areas in Kuantan. For this part of the study, one sewer pipeline (MH92a–MH92b) was selected at the residential area of Bandar Putra, having a population equivalent of 1694. The method used in this research was the Flowrate method to tabulate data. ISCO 2150 and 4250 Area Velocity Flowmeters were used to measure flow rate data in the sewer pipeline, whereas ISCO 674 Rain Gauge was used to collect rainfall intensity data. Calibration of all the equipment was done at the Hydrology and Hydraulic Laboratory in UMP. The data was collected for 41 days with each measurement separated by an interval of five minutes. The result shows that the average percentage Infiltration Rate of Qpeak and Qave in this residential catchment were 10.3% and 26.5% which is higher than the value mentioned in Hammer and Hammer (2012). Inflow and infiltration is a real concern, so more study is required to determine whether revision of the infiltration rate recommended in the Malaysian Standard is needed

    Passive Microwave Remote Sensing for Sea Ice Thickness Retrieval Using Neural Network and Genetic Algorithm

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    Abstract-Over the years, global warming has gained much attention from the global community. The fact that the sea ice plays an important role and has significant effects towards the global climate has prompted scientists to conduct various researches on the sea ice in the Polar Regions. One of the important parameters being studied is the sea ice thickness as it is a direct key indication towards the climate change. However, to conduct studies on the sea ice scientists are often facing with tough challenges due to the unfavorable harsh weather conditions and the remoteness of the Polar Regions. Thus, microwave remote sensing offers an attractive mean for the observation and monitoring of the changes of sea ice in the Polar Regions for the scientists. In this paper, we will be presenting 2 approaches using passive microwave remote sensing to retrieve sea ice thickness. The first approach involves the training and testing of the neural network (NN) by using data sets generated from the Radiative Transfer Theory with Dense Medium Phase and Amplitude Correction Theory (RT-DMPACT) forward scattering model. Once training is completed, the inversion for sea ice thickness could be done speedily. The second approach utilizes a genetic algorithm (GA) which would perform a search routine to identify possible solutions in sea ice thickness that would match the corresponding brightness temperatures profile of the sea ice. The results obtained from both approaches are presented and tested by using Special Scanning Microwave Imager (SSM/I) data with the aid of the sea ice measurements in the Arctic sea

    Eosinophils in Oral Disease: A Narrative Review

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    The prevalence of diseases characterised by eosinophilia is on the rise, emphasising the importance of understanding the role of eosinophils in these conditions. Eosinophils are a subset of granulocytes that contribute to the body's defence against bacterial, viral, and parasitic infections, but they are also implicated in haemostatic processes, including immunoregulation and allergic reactions. They contain cytoplasmic granules which can be selectively mobilised and secrete specific proteins, including chemokines, cytokines, enzymes, extracellular matrix, and growth factors. There are multiple biological and emerging functions of these specialised immune cells, including cancer surveillance, tissue remodelling and development. Several oral diseases, including oral cancer, are associated with either tissue or blood eosinophilia; however, their exact mechanism of action in the pathogenesis of these diseases remains unclear. This review presents a comprehensive synopsis of the most recent literature for both clinicians and scientists in relation to eosinophils and oral diseases and reveals a significant knowledge gap in this area of research
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